Wisdom, easily identified by her red colour band Z333, Midway Atoll, 24 November 2022.  Photograph by Keegan Rankin, U.S. Fish and Wildlife Service

Wisdom, a female Laysan Albatross Phoebastria immutabilis, the world’s oldest known wild bird, was sighted back on Midway Atoll in the northern Pacific Ocean on 24 November 2022.  She is considered to be at least 71 years old.  First banded by the late Chandler Robbins in 1956 as a breeding adult and thus at least five years of age, she could be much older.  According to Jonathan Plissner, supervisory wildlife biologist at the Midway Atoll National Wildlife Refuge, it has been estimated that Wisdom has produced 50-60 eggs and as many as 30 chicks that fledged successfully over her lifetime.

Her mate, Akeakamai, has yet to be seen this breeding season.  Wisdom has not been seen  since her first sighting last month and as most Laysan Albatrosses have already laid their eggs on Midway it seems she will not be breeding for another year (click here).  The Facebook page of the Pacific Islands: U.S. Fish and Wildlife Service states that Wisdom's interactions with other birds in the vicinity and the absence of Akeakamai suggest that Wisdom might be widowed, noting the male of the pair usually arrives on the atoll before their female mate.  In the previous season Wisdom returned to her nest site for only two days in November and was not then seen interacting with neighbouring birds.

Click here to access the many posts about Wisdom in ACAP Latest News over the last decade.

John Cooper, ACAP News Correspondent, 13 December 2022

Figure 1. Schematic of a wandering albatross flying in an across-wind direction using an S-shaped dynamic soaring manoeuvre consisting of a series of upwind and downwind turns through the boundary layer (redrawn after Sachs [6]). The bird extracts mechanical energy from the wind by climbing headed upwind and descending headed downwind. Wave heights are typically large in the Southern Ocean. Wind–wave interactions cause a more complicated instantaneous wind field than the average shown here, and waves themselves induce updrafts. Albatrosses appear to efficiently exploit these fine-scale variations in wind velocity, making modelling their flight challenging. 

Philip Richardson (Department of Physical Oceanography, Woods Hole Oceanographic Institution, USA) and Ewan Wakefield have published open access in the journal Royal Society Open Science an analysis of the wandering albatrosses’ utilisation of dynamic soaring using GPS tracking data and model simulations.

The paper’s abstract follows:

Wandering albatrosses exploit wind shear by dynamic soaring (DS), enabling rapid, efficient, long-range flight. We compared the ability of a theoretical nonlinear DS model and a linear empirical model to explain the observed variation of mean across-wind airspeeds of GPS-tracked wandering albatrosses. Assuming a flight trajectory of linked, 137° turns, a DS cycle of 10 s and a cruise airspeed of 16 m s⁻¹, the theoretical model predicted that the minimum wind speed necessary to support DS is greater than 3 m s⁻¹. Despite this, tracked albatrosses were observed in flight at wind speeds as low as 2 m s⁻¹. We hypothesize at these very low wind speeds, wandering albatrosses fly by obtaining additional energy from updrafts over water waves. In fast winds (greater than 8 m s⁻¹), assuming the same 10 s cycle period and a turn angle (TA) of 90°, the DS model predicts mean across-wind airspeeds of up to around 50 m s⁻¹. In contrast, the maximum observed across-wind mean airspeed of our tracked albatrosses reached an asymptote at approximately 20 m s⁻¹. We hypothesize that this is due to birds actively limiting airspeed by making fine-scale adjustments to TAs and soaring heights in order to limit aerodynamic force on their wings.

An article explaining the paper’s findings has been released by Woods Hole Oceanographic Institution (WHOI) on their website.

Reference:

Richardson P.L. and Wakefield E.D. 2022 Observations and models of across-wind flight speed of the wandering albatross Royal Society Open Science. 9211364211364 http://doi.org/10.1098/rsos.211364

12 December 2022

ACAP Secondee Maximiliano Hernandez (right) with Dragonfly's Environmental Data Scientist, Yvan Richard (left); photograph courtesy of Sarah Wilcox

There may have been a delay of two-years for Argentinian Maximiliano Hernandez to complete his secondment developing an Ecological Risk Assessment within a framework of seabird conservation, but from his perspective, it was worth the wait. Maximiliano had initially planned for the secondment to take place in November 2020, however the COVID-19 pandemic put his travel to New Zealand on hold.

Maximiliano is a PhD student at the Institute of Marine and Coastal Research, National University of Mar del Plata in Argentina, and is interested in the development of Ecological Risk Assessments specific to species known to interact with Argentinian fisheries, which includes a number of ACAP-listed species. 

His successful application to ACAP’s Secondment Programme in 2019 included the New Zealand Department of Conservation facilitating opportunities for Maximiliano to work with experts in ecological risk assessment whilst ACAP provided funding for travel and living expenses during the proposed project. 

A Black-browed Albatross - one of the first species, alongside the White-chinned Petrel, Maximiliano chose for his first assessments due to the abundance of population data and their high catch rates in Argentinian fisheries; photograph by Maximiliano Hernandez

Maximiliano was afforded the opportunity to work under the guidance and expertise of Dr Yvan Richard, an Environmental Data Scientist with Wellington-based company, Dragonfly Data Science. Yvan has over 10 years’ experience in carrying out Ecological Risk Assessments and introduced Maximiliano to several programming tools used to write code for the assessments, skills which will benefit not just Maximiliano but his Argentinian colleagues on his return. The results of the analyses will contribute to the effective implementation of Argentine NPOA-Seabirds.

Capacity building through the fostering of collaboration and knowledge-sharing between Parties are key tenets that underpin the philosophy of the ACAP Secondment Programme. The ACAP Secretariat is delighted to finally report on the successful completion of Maximiliano’s secondment, which highlights how a collaborative approach between Parties serves the Agreement in striving toward its central purpose - to improve conservation outcomes for all ACAP-listed species.

Read more about Maximiliano and his time spent with Yvan Richard in Dragonfly’s article on the project by Sarah Wilcox (link). 

9 December 2022

Balearic Shearwater by Anju Rajesh, after a photograph by 'Pep' Arcos

Joan Ferrer Obiol (Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Spain) and colleagues have published open access in the journal Molecular Phylogenetics and Evolution, finding that current taxonomies do not provide an accurate delineation of North Atlantic and Mediterranean Puffinus shearwaters.  Based on their genetic study, they propose Yelkouan and Balearic P. mauretanicus Shearwaters should not be given specific status but be regarded as subspecies of the Mediterranean Shearwater P. yelkouan.

The authors state that the two taxa “are good examples of differentiated populations worthy of consideration as intraspecific units that represent unique morphological, ecological and genetic diversity for conservation of biodiversity.  We stress that developing action plans for P. mauretanicus and P. yelkouan should not depend on whether these taxa are classified as separate species or not.”

A  banded Yelkouan Shearwater in Malta, photograph by Andre Raine

The paper’s abstract follows

“Speciation is a continuous and complex process shaped by the interaction of numerous evolutionary forces. Despite the continuous nature of the speciation process, the implementation of conservation policies relies on the delimitation of species and evolutionary significant units (ESUs).  Puffinus shearwaters are globally distributed and threatened pelagic seabirds. Due to remarkable morphological status the group has been under intense taxonomic debate for the past three decades. Here, we use double digest Restriction-Site Associated DNA sequencing (ddRAD-Seq) to genotype species and subspecies of North Atlantic and Mediterranean Puffinus shearwaters across their entire geographical range. We assess the phylogenetic relationships and population structure among and within the group, evaluate species boundaries, and characterise the genomic landscape of divergence. We find that current taxonomies are not supported by genomic data and propose a more accurate taxonomy by integrating genomic information with other sources of evidence. Our results show that several taxon pairs are at different stages of a speciation continuum. Our study emphasises the potential of genomic data to resolve taxonomic uncertainties, which can help to focus management actions on relevant taxa, even if they do not necessarily coincide with the taxonomic rank of species.”

Read an ACAP Monthly Missive on listing more shearwaters on the Agreement, including the Yelkouan, here.

Reference:

Species delimitation using genomic data to resolve taxonomic uncertainties in a speciation continuum of pelagic seabirds.  Molecular Phylogenetics and Evolution  179.  doi.org/10.1016/j.ympev.2022.107671.

John Cooper, ACAP News Correspondent, 08 December 2022